Hi, I'm looking into buying a new camera which I'll be using both on land as well as underwater. Any suggestions on what currently is the best camera for both purposes?

Are you looking for a "point and shoot"? If so, I would have a look at the Panasonic DMC-TS4. The earlier version (TS3) stood up very well to the competition in a group review on another site and I have been quite pleased with mine... took it snorkeling in Hawaii a few months ago and it did quite well.